Ukraine has carried out a series of deadly air strikes on targets in south-west Russia over the past 24 hours, according to Russian officials.
Russia's emergency ministry says 10 people including a child were killed and more than 40 injured in the city of Belgorod.
Earlier, Russia's defence ministry said it had destroyed dozens of missiles and drones fired from Ukraine.
The attacks follow Russian strikes on Ukraine which killed 39 people.
Those strikes were described by Kyiv as Russia's biggest missile bombardment of the war so far against Ukraine.
Ukrainian media - citing intelligence sources - is reporting that more than 70 drones were used in a series of attacks on Russia and only military targets were attacked. They added that a group of drones successfully hit a electronic factory in the Bryansk region used to make Russian military equipment like long-range missiles and anti-aircraft systems.
Russia's president has been briefed on the attacks, his spokesperson said.
An initial statement from the Russian defence ministry on Saturday said 13 missiles were destroyed over the wider region overnight.
Later, it said 32 drones had been shot down in the Bryansk, Oryol, Kursk and Moscow regions.
The governor of Bryansk region meanwhile said two villages were targeted and a child, born in 2014, had been killed.
He said the attacks had damaged 55 homes, two private businesses, a football ground, a leisure centre and a pre-school.
Moscow has repeatedly accused Ukraine of being behind drone strikes in recent months, though Ukraine has not claimed responsibility for these.
The strikes come after Russia launched a massive bombardment across Ukraine, killing 39 people and injuring nearly 160. Several cities were hit, including the capital, Kyiv.
Mayor of Kyiv Vitali Klitchsko said on Saturday that at least 16 people were killed in the city, making it the deadliest so far for civilians in the capital.
On Friday evening, an emergency meeting of the UN Security Council overwhelmingly condemned Russia's renewed mass-bombing campaign in Ukraine and said attacks must stop "immediately".
Countries including the US, UK and France said hitting civilian infrastructure had violated the international rules of war.
"Rather than peace, Putin chose to mark this holiday season... with an unprecedented number of drone and missile attacks," US representative to the UN John Kelley said.
Russia said Ukrainian air defences were to blame for causing damage to civilian buildings.
Source: BBC
